Likely B. Liquidity is basically the measurement of how quickly a given investment can be turned into cash. If you can sell it or take money from it quickly, it is liquid. Any one of the others (A, C or D) can be withdrawn from in a short time, and thus are very liquid. CDs, however, are set to a specified amount of time. You deposit money for, say, 5 years and then are allowed to withdraw it, not before. Thus, it is not liquid.
